Printing system for labels

Abstract: A printing system is described for use with linerless adhesive coated label stock (36). A print head (32) is disposed close to an endless belt (40) and the stock passed therebetween so that labels are printed on one side and adhered on the other side to the belt. Downstream of the print head the belt makes an abrupt change of direction which is effective to detach the now printed label stock therefrom.

Description: The present invention relates to the printing of merchandising labels for wrapped packages. In product merchandising, such as in the supermarket business for example, products are wrapped typically in stretch or shrink film, then conveyed to a labeler which automatically prints and attaches a label to the product package giving price. or other information about the product. The labels are provided in the form of a narrow continuous strip of paper stock and are joined at tearable perforations so that individual labels may be printed and separated from the strip for attachment to the package. Label stock of the type currently in use is supplied in roll form. The labels are made from thermosensitive paper and have an adhesive backing on them so that they will adhere to the plastic wrapping of the package. In order to keep the labels from sticking to themselves while in roll form or during handling, the labels are mounted on a continuous backing, or liner. The typical liner is a paper material coated on one side with silicone. The silicone coating allows the labels to be readily separated from the liner prior to attachment to a package. A disadvantage of using such conventional label stock having a liner is that the spent liner must be collected and disposed of. This typically involves providing a take-up reel for storing the used liner. The reel must be changed periodically in the operation of the labeling machine and the full reel must be discarded or replaced with an empty reel, involving down time of the label machine. Label stock can be supplied in a linerless form. That is, the label material may be supplied in roll form but without a silicone-coated backing paper. The labels are coated on their print side with silicone so that their adhesive side will not stick appreciably to the print side when in roll form. A significant problem arises with using such linerless label stock in that the adhesive side of the labels tends to adhere to the conveying members when the label stock is transported through the printer. This is particularly a problem at the thermal print head where the label must be pressed against the print head to obtain an acceptably printed label. The typical means for pressing the label against the print head is neoprene roller juxtaposed next to the print head. Without a liner, the label stock will adhere to the print roller and be incapable of being transported to the package. FR-A-2414763 discloses an apparatus for printing labels which have bands of release material on one face thereof and corresponding bands of adhesive on the other face. The labels are carried by an endless carrier belt, to which the adhesive face of the label sticks, past a cutter and are then printed by a marker. The continued movement of the carrier belt carries the printed label to a point at which it detaches itself from the belt and the printed label is then pressed onto a package by a roller. The present invention seeks to overcome the problems described above and to enable linerless label stock to be printed and employed in a commercial package labelling machine. In accordance with a first aspect of the present invention, there is provided apparatus for printing linerless labels having an adhesive coating on one side thereof, comprising a print head for printing indicia on the print side of the labels, a print roller disposed in close proximity to the print head and adapted to press the labels against the print head during printing, and an endless belt adapted to travel around the print roller, and a peel bar is positioned in spaced relation to the print roller and within the endless belt, wherein the labels are adhered to the belt at the print head and are conveyed to the peel bar where they are released from the belt. In a second and alternative aspect thereof, the invention provides an apparatus for printing linerless labels having an adhesive coating on one side thereof comprising a print head for printing indicia on the print side of the labels, a print roller disposed in close proximity to the print head and adapted to press the labels against the print head during printing, and an endless belt adapted to travel around the print roller, and an idler pulley is positioned within the endless belt, wherein the labels are adhered to the belt at the print head and are released from the belt as the belt travels around the print roller. The invention provides, in a third alternative aspect thereof, a method of printing indicia on a strip of printable material having an exposed adhesive coating on one side thereof comprising the steps of positioning a roller and a peel bar in spaced parallel relation to one another, rotating an endless belt around the roller and peel bar such that the belt makes an abrupt change of direction at the peel bar, positioning a print head in close proximity to the roller, passing the strip of material between the print head and roller with the adhesive coating facing the roller such that indicia is printed on the strip and the strip is adhered to the belt and detaching the strip from the belt as the belt passes around the peel bar. According to a fourth alternative aspect thereof, the invention provides a method for printing indicia on a strip of printable material having an exposed adhesive coating on one side thereof comprising the steps of positioning a first roller and an idler second roller in spaced parallel relation one to another, rotating an endless belt around the rollers such that the belt makes an abrupt change of direction at the first roller, positioning a print head in close proximity to the first roller, passing the strip of material between the print head and the first roller with the adhesive coating facing the roller such that indicia is printed on the strip and the strip is adhered to the belt and detaching the strip from the belt as the belt passes around the first roller. The invention is hereinafter more particularly described by way of example and with reference to the accompanying drawings, in which:- Fig. 1 is a schematic view of a prior art label printing apparatus for use with conventional label stock having a liner; Fig. 2 is a schematic view of an embodiment of label printing apparatus in accordance with the invention for use with linerless label stock; and Fig. 3 is a schematic view of an apparatus in accordance with another embodiment of the present invention. Referring initially to Fig. 1, a prior art label printing apparatus, designated generally by the reference numeral 10, includes a conventional thermal print head 12 disposed in close proximity to a print roller 14. Label stock 16 is supplied from a supply reel 18. The label stock 16 includes thermally sensitive paper 20 backed by a relatively non-stick liner 22. When the printing apparatus 10 is in operation, the label stock 16 is fed between the print head 12 and print roller 14 whereupon appropriate indicia is printed on the label paper 20. In the configuration illustrated, the print side of the label stock 16 is facing downwardly while the liner 22 is on the upward side of the label stock 16. After the label stock 16 passes between the print head 12 and roller 14 the label stock travels to a peel bar 24 where the liner 22 is stripped from the label paper 20. The used liner 22 then proceeds around the peel bar 24 to a take-up reel 26 on which it is stored for later disposal. The label paper 20 continues to advance, with its adhesive side exposed, to a package labeling station (not shown). Turning now to Fig. 2, the illustrated embodiment of label printing apparatus in accordance with the invention is designated by the reference numeral 30 and includes a conventional thermal print head 32 positioned adjacent a print roller 34. Label stock 36 of the linerless type is provided from a supply reel 38 with its adhesive side up, as viewed in FIG. 2. The label stock 36 passes between the print head 32 and print roller 34 where it is intercepted by an endless belt 40. The endless belt 40 passes around a peel bar 42, the print roller 34 and an idler pulley 44. The idler pulley 44 is tensioned by a suitable biasing means 46 so that the belt 40 remains taut as it is driven by the print roller 34. The belt 40 is preferably formed from a fabric material coated on its outward surface with silicone. A porous roller 48 filled with liquid silicone may be positioned in contact with the belt 40 to apply a continuous film of silicone to the belt surface. In operation of the apparatus 30 it can be appreciated that as the strip of linerless label stock 36 passes between the print head 32 and roller 34, where it is intercepted by the endless belt 40, the adhesive of the labels 36, which is facing upwardly as viewed in FIG. 2, causes the labels 36 to adhere to the belt 40 and be transported to the peel bar 42. At the peel bar 42 the belt 40 makes an abrupt change of direction causing the belt 40 to separate from the label strip 36, whereupon the strip of labels 36 is free to proceed substantially in a straight line from the supply reel 38 through the printer 32 and then to a label applying station (not shown). The belt 40 thus serves as a temporary liner for the label stock 36 during the printing process and completely eliminates the need for linered label stock. Fig. 3 illustrates another embodiment of our apparatus in which the belt passes around idler rollers 44 and 45 and the peel bar 42 is located outside the endless belt 40 adjacent to the print roll 34 where the peel bar functions to direct the labels 36 to the label applying station. In this embodiment, the print roll 34 has a small enough diameter that the labels separate from the belt 40 as the belt passes around the print roll 34 without positioning the peel bar 42 within the belt 40. Because the labels separate from the belt as the belt passes around the print roll and the peel bar functions merely to direct the labels to the label applying station, the peel bar could be eliminated altogether and other means can be used to direct the labels to the label applying station.

Claims: Apparatus for printing linerless labels having an adhesive coating on one side thereof, comprising a print head (32) for printing indicia on the print side of the labels (36), a print element (34) disposed in close proximity to the print head (32) and adapted to press the labels (36) against the print head (32) during printing, and an endless belt (40) adapted to travel around the print element (34), wherein the labels are conveyed by the belt and adhered to the belt at the printing head, characterised in that the print element is in the form of a print roller, and in that a peel bar (42) is positioned in spaced relation to the print roller (34) and within the endless belt (40), wherein the labels (36) are conveyed to the peel bar (42) where they are released from the belt (40). Apparatus according to Claim 1 comprising an idler pulley (44) with the belt (40) travelling around the print roller (34), peel bar (42) and idler pulley (44). Apparatus according to Claim 1 or 2 comprising means (48) for applying a non-stick coating to the belt (40) as the belt (40) is travelling around the print roller (34) and peel bar (42). Apparatus for printing linerless labels having an adhesive coating on one side thereof, comprising a print head (32) for printing indicia on the print side of the labels (36), a print element (34) disposed in close proximity to the print head (32) and adapted to press the labels (36) against the print head (32) during printing; and an belt (40) adapted to travel around the print element (34) wherein the labels (36) are adhered to the belt (40) at the print head (32) and are released from the belt (40) as the belt (40) travels around the print element (34), characterised in that the print element is in the form of a print roller, and in that an idler pulley (44,45) is positioned within the endless belt (40). Apparatus according to Claim 4 characterised in that a peel bar (42) is positioned outside of the belt (40) adjacent the print roller (34) such that the peel bar (42) directs the labels (36) away from the belt (40). A method of printing indicia on a strip of printable material having an exposed adhesive coating on one side thereof comprising the steps of positioning a roller (34) and a peel bar (42) in spaced parallel relation to one another, rotating an endless belt (40) around the roller (34) and peel bar (42) such that the belt (40) makes an abrupt change of direction at the peel bar (42), positioning a print head (32) in close proximity to the roller (34), passing the strip of material (36) between the print head (32) and roller (34) with the adhesive coating facing the roller (34) such that indicia is printed on the strip (36) and the strip (36) is adhered to the belt (40) and detaching the strip (36) from the belt (40) as the belt (40) passes around the peel bar (42). A method of printing indicia on a strip of printable material having an exposed adhesive coating on one side thereof comprising the steps of positioning a first roller (34) and a second, idler roller (44) in spaced parallel relation one to another, rotating an endless belt (40) around the rollers (74,44) such that the belt (40) makes an abrupt change of direction at the first roller (34), positioning a print head (36) in close proximity to the first roller (34), passing the strip of material (36) between the print head (32) and the first roller (34) with the adhesive coating facing the roller (34) such that indicia is printed on the strip (36) and the strip (36) is adhered to the belt (40) and detaching the strip (36) from the belt (40) as the belt (40) passes around the first roller (34).

Inventors: BEATY DAVID P, SCHROEDER KARL, BEATY, DAVID P, SCHROEDER, KARL
Applicants: PREMARK FEG CORP, PREMARK FEG CORPORATION
Application year: 1994
Main classification: B65C9
IPC codes: B65C9, B41J15, B41J11